Gauge for small screw threads



Filed June 29, 1946 INVENTOR C. GfJVPWZO/L ATTO RN EY Patented July 18, 1950 UNITED STATES 2,515,418 y H GAUGE FOR SMALL SCREW: THREADS Chauncey G. Newton, Rochester, N. Y., assignor to Niles-Bement-Pond Company, West Hartford, Conn., a corporation of New Jersey v Application June 29, 1946; Scrial'No; 680,433

This invention relates to dimension gages and particularly to a, screw thread gage adapted to quickly and accurately gage short external screw threads of small diameter.

,A- primary object of the invention is to provide means to resiliently retain a threaded workpiece being gaged inposition within a holder, the holder and work-piece being mounted for movement between opposed work contacting members of the gage. 1: o

A feature that enables thistobject to be accomplished is-thati a'work' pieceq support is pivotally mounted adjacent the gage,: which, may be of standard snap gage type,"the pivotal support having a, work. retaining armoutstanding therefrom between the forked ends of which the work piece being gaged may be resiliently retained, the pivotally mounted member being manually moved to guide the work piece supported at the end of the-arm between the work contacting members of the gage.

Another object of the invention is to provide a pressure controlled switch on the work supporting member so that when a predetermined pressure is required to move the supporting member to pass a work piece between the gaging members during the gagingop'eration a signal such as a small light will be operated.

Another feature that is advantageous in this connection is that the pressure operated switch is controlled by the manual means or handle made use of to oscillate the pivotally supported work piece to support and guide the work piece when moved duringthegaging operation between the work contacting members, of the gage.

With the above and other objects in view, the invention consists in the features of construction and operation set forth in the following specification and illustrated in the accompanying drawing.

In the accompanying drawing annexed hereto and forming a part of this specification, the invention is shown embodied in a manually operated screw thread gage for smal1 threaded members, but itwill be understood that the invention can'be otherwise. embodied andithat the drawings are-not .to be construed as? defining or limiting the scope of the invention, the claims appended to this specification being relied upon for that purpose.

In the drawing:

Figure 1 is a side elevation, partly in section, of a complete gage made in accordance with the present invention.

n '3 Claims. (01. 33-199) 2 Fig.- 2 is a plan view of a portion of the gage shown in Fig. 1. v

Fig.3 is a detail end view of a form of work piece retaining member on anenlarged scale, and

Fig. 4 is adiagram of the signal-operating circuit.. I.

- Briefly, and in its: broadest aspect, the invention may comprise: First, a base on which is mounted a standard form of screw thread snap gage; second, a' pivotally mounted member on the said base havinga work retaining arm outstanding therefrom; third, a, pressure operated switch on the pivotally mounted member; and fourth, asignal controlled by operation of the pressure switch.

Referring more in detail to the figures of the drawing, it will be seen that a base orplatform I 0 is provided on which is adjustably mounted a screw thread snap gage l2 of the well-known Johnson snap. type, this gage preferably having two 'pairs ofopposed freely rotatable annularly grooved rolls between which the threaded work piece W being gaged may be passed. A- gage of this type isshow'n in'Patent No; 1,660,335granted February 28, 1928. The first'or outer pair of work contacting. rollers. l| -l3 is so adjusted that a work piece of full size but not oversize will pass between them, but if it is undersize, it will also pass through'a second or lower pair of rolls I 5-41, which are so "adjustedthat they will not permit any, workpiece too'large to pass inspection to pass through. A member W being gaged is with in specifications only if it'passes between the first pair of rolls H-l 3;but does not pass between the second pair 15-41.

At one side" of this "gage i2" is a bracket l4 rigidly fixedtin' position relative to the base 10 and having a pivotally. mounted member i6- mounted thereon; Thegage l2 is-mounted on this bracket in a manner permitting ready substitution of different gagesr Supported transversely within this member l6 and suitably fixed thereon is a horizontally extending cylindrical arm l8, the outer'end po'rtion's of' which are milled off on opposite sides and forked so that the'g'ap' milled on" so that it is of less thickness than the root diameter of the screw threads being gaged. The work piece supported between these forked ends of arm I8 therefore will enter the gap between the gaging rolls I II3 and I5I'I or other 5 contacting members of the gage. This work retainer or arm I8 is, as shown, mounted detachably but fixedly as by a screw 2| within the pivotally mounted member I6 so that substitute retaining members I8 may be easily changed to .10, adapt the gage for a wide variety of screw threads.

To adjust the position of the axis orpivot I9 about which the member I6 oscillates, a clamping screw I5 is provided to clamp the pedestal 23 for the member I6 in any adjusted position along the arm I4 so that the work holder I8 may be located accurately relative to the particular 'gage'f I2 being used. For this purpose the arm 14 is provided with an elongated slot through which clamping screw I5 extends. 20

'In order to. oscillate this pivotally mounted member I6 aboutits pivot I9 in the bracket I4 to present the work piece between the gaging members, a flexible arm or handle 24 is mounted resiliently therein as by means of a thin flexible as 1 intermediate section. This handle 24 maybe resiliently forced in one direction as by a spring 24 attached to member I6. Movements of Lthis arm 24 relative to the pivotally supported member I6 are limited by any appropriate stops 29 and M as shown. Also mounted on this pivotally sup ported member I6 is a pressure operated switch 1 26 of any conventional or standard type so that 1 when a predetermined pressure is exceeded in passing the work piece W through the space beas tween the gaging members II -I3 and I5'I'I by depressing handle 24,th ehandle will be resiliently I moved further downward and will operate the pressure operated switch 26. Associated with j the switch is a signal light 28 or other electrically I operated signal means so that when'the switch By means of the handle 24 the pivotally supported member I6 is then manually oscillated downward. In the event that the member'W being gaged is oversize and will not pass through the gap between the first pair of rollers III3, the

resilient handle 24 will move relative to the pivotally mounted member l6 and actuate the 1 switch 26 to either light orextinguish the signal bulb 28. The pressure necessary to operate this switch may be adjusted as desired and the position of the work contacting members of the gage I2 may be so spaced that a member W within the desired tolerances'will pass through the'first pair of rolls I |'I 3 without operating the pressure switch 26 and without lighting or extinguishing the signal bulb 28. The second pair of rolls I5I 1 55 will be so set that if the gage piece W is properly I made the Work piece will not pass the second pair of gaging members, and the arm 24 will therefore be resiliently disposed relative to the pivotally supported member I6 and the switch 26 will be operated to afiect the bulb 28.

Normally, a light spring 30 holds the pivotal member I6 in inoperative or upper position and the movement of the handle 24 relative to the pivota1 member I6 requires a greater pressure to operate the switch lever 26 than that necessary to overcome the pressure of spring 30 and move member I6.

A simple circuit is shown for the signal bulb 28 in Fig. 4. The bulb 28 may be adapted for a lower voltage than the available source so that resistances 32 are'provided. Also the switch 26 may be so mounted that normally its circuit is closed and the light 28 is on when no pressure is applied to the handle 24 suflicient to deflect it relative to the pivotal member I 6. As soon, however, as handle 24 is moved relative to the member l6, lever 26 within the switch housing 21 is moved to open the switch contacts. I

I claim:

1. A gage comprising in combination, a base, a pair of work contacting gaging rolls mounted thereon, a pivotally mounted member on said base,fa work piece retainer on said member adapted to support the work piece in position for movement between said rolls when said member is actuated, a pressure operated switch on said member, and a signal operating circuit closed by operation of said switch, said signal being operated by the pressure of said member necessary to move work pieces between said rolls.

2. A gage comprising in combination, a base, a pair of work contacting gaging rolls mounted on fixed axes thereon, a pivotally mounted member on said base, a work piece retainer on said member adapted to resiliently support the work piece with its axis in parallel relation to theaxes of said rolls when said member is actuated, a pressure operated switch on said member, and a signal operating circuit closed by operation of said switch, said signal being operated by the pressure of said member necessary to move work 45 pieces between said rolls.

3. A screw thread gage comprising in combination, a base, a pair of annularly grooved work contacting rolls mounted thereon, apivotally mounted member on said base, a work piece retainer on said member adapted to support a work piece in position for movement between the REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,645,118 Seabright Oct. 11, 1927 1,851,283 Johnson Mar. 29, 1932 2,345,867

Du Pont et a1 Apr. 4, 1944 

